One can find their version of Windows 8 by going to the Control Panel, System and Security, System (or right click on Computer, and "Properties"). It will say something like "Windows 8", "Windows 8 Pro", or "Windows 8 Enterprise". You'll see something like this:
Note the checkmark I placed. Alternatively, one may open a cmd window and type the following command:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"
There's also Windows 8 RT, but that is found only on tablets, not computers.